In order to allow a semiconductor device such as a metal oxide semiconductor field effect transistor (MOSFET) to be high in breakdown voltage and low in loss and to be used in a high-temperature environment, silicon carbide has recently increasingly been adopted as a material forming a semiconductor device. Silicon carbide is a wide band gap semiconductor greater in band gap than silicon which has conventionally widely been used as a material forming a semiconductor device. Therefore, by adopting silicon carbide as a material forming a semiconductor device, a higher breakdown voltage and a lower on-resistance of a semiconductor device can be achieved. A semiconductor device in which silicon carbide has been adopted as a material is also advantageous in that lowering in characteristics during use in a high-temperature environment is less than in a semiconductor device in which silicon has been adopted as a material.
For example, Japanese Patent Laying-Open No. 2012-146838 (PTD 1) describes a MOSFET having an n-type source region, a p-type body region, and an n-type SiC region. According to the MOSFET described in Japanese Patent Laying-Open No. 2012-146838, as a voltage is applied to a gate voltage, an inversion layer is formed in a channel region in the p-type body region directly under a gate insulating film and a current flows between a source electrode and a drain electrode.